Antifriction metaling of bearings



Patented Apr.30,1940 a r 2,199,125 v UNITED STATES PATENTQFFICE ANTIFRICTION METALING or names Marius Jean-Baptiste Barbarou, Neuilly/Seine,

' France v 'No Drawing. Application February 19, 1938, Se,- rial No. 191,517. In France February 19, 1937 3 Claims. (Cl. ill-70.3)

The present invention relates to the coating of more according to the thickness of the layer deferrous metals and alloys with a layer of metal sired and at a temperature of approximately having important frictional characteristics, and 900 C. The cemented bearing will then be imin particular alloys with a base principally of tin, mersed in a solution of hydrochloric acid to re-,

5 with. very diverse compounds such as antimony, move all traces of fatty bodies and then in hy- 5 lead, zinc cadmium or other bodies; these alloys drofluoric acid to dissolve the silica immediately being usually termed -antifriction metal and formed by oxidation of the silicon when hot. the invention has for its object a novelprocess 'Any trace of silica would prevent the combinaand means for carrying out the said process in tion of the silicon and tin, forming an absolute order toobtain perfect adherence of the coating screen. 10 on' the metals in question. After passing through a solution of zinc chlo- It is known that the application of such coat- .ride, the bearing is tinned at about 350 C. and ings is to be preceded by a tinning of the metals dipped several times in the chloride of zinc and or alloys to be treated and that the diffusion of in the tin bath.

the tin in iron is difficult at ordinary tempera- The antifriction metaling should be carried 5 tures; so that the tinning has only a restricted out immediately afterwards. adhesion on the ferrous alloys. The result is It is important that these various operations that in the course of working under loads which be carried out as quickly as possible to avoid any are generally heavy, a scaling or detachment of A partial reoxidation of the surfaces. the antifriction metal takes place. The use of the silicon only serves as intermedi- 20 The present invention presents'a simple means ary to facilitate the metallic combination of iron for overcoming these difliculties and is cha'racand tin which, as is known, is very incomplete at terised in particular by the introduction of silithe ordinary tinning temperatures. Any other con into the ferrous alloys, inthe course of an body than silicon giving the same result is comordinary cementation with ferro-silicon, thus prised within the scope of the invention. 25

forming at the surface of the alloy a metallic What I claim as my invention is: combination of iron'and silicon; ,1. A process for bonding an antifriction coat- Following this the tinning isproceeded with, ing to iron and ferrous alloys, comprising the after certain precautions which will be more exstep of subjecting the surface to be treated to plicitly dealt with hereafter, which operation is a silicon cementation, applying a tin coating to 36 ossible at the usual ordinary temperatures, utlsaid cemented surface, and thereafter fusing to lising to this end the natural 'aflinity of silicon said tin coating a layer of antifrlction metal. -i for tin, or vice versa. Consequently, this tinning 2. In a process of the character described, the adheres very strongly to the shell, the presence steps of subjecting an iron or ferrous alloy surof the silicon enabling it to diffuse regularly to face to a cementation with ferrosilicon at a tem- 35 the interiorofthe metal. perature of'900" C. for a period of from 5 to 20 The coating or antifn'ction metalising proper hours, acid-cleaning the cemented surfaces to may be carried out in the ordinary way without remove .silica, applying a tin coating to the special centrifugatlon. cleaned surfaces, and thereafter fusing to the 40 In order that the process which-has been detin an antifriction metal layer. 4o scribed shall have satisfactory results, suitable 3. A process for bonding .an antifriction coatprecautions should be taken in carrying it out. into iron and ferrous alloys, comprising the 'Presuming that it is desired to provide a bearsteps of subjecting the surface tobe treatedto a ing with antifriction metal by the process desilicon cementation, applying zinc chloride to scribed, the following-or a similar procedure said cemented surface, tinning thecemeiited Sll1- 4 6 should-be adopted. face, and thereafter fusing to said tinned sur- Th'e bearing'should be first cemented with face a layer of antifriction metal.

ferro-silicon for a period 'of 5 to 20 hours or MARIUS JEAN-BAPI'ISTE BARB AJROU. 

